Processors exchange data over a bus to communicate with other devices and other processors. A typical arrangement includes a two wire device utilizing a universal asynchronous receiver/transmitter (UART) to communicate with one or more devices such as slave processors. A bus allows multiple devices to communicate over one or more conductors such as wires. Due to design limitations related to size, supply power, and other factors, it is often advantageous to limit the number of pins on packaged electronic devices, wires, and other conductors. A single conductor bus allows for fewer pins and conductors as compared to multiple conductor buses. Conventional designs utilizing single conductor buses, however, are limited in that the devices connected to the single conductor bus must operate at the same voltage as the devices communicating on the two conductor bus.
Accordingly, there is need for a level shifting multiplexing circuit for connecting a two conductor full duplex bus to a bidirectional single conductor bus.